The preliminary investigation is the latest in a series of legal wrangles at Uber as the ride-services company waits for its new chief executive to take the reins.

A spokesman for the company confirmed the existence of a "preliminary investigation" following a report by the Wall Street Journal on Tuesday that the Justice Department had started probing whether managers at Uber violated U.S. laws against bribery of foreign officials, specifically the Foreign Corrupt Practices Act.

It is unclear whether authorities are focussed on one country or multiple countries where the company operates.

Reuters in June reported that Uber had hired a law firm to investigate how it obtained the medical records of an Indian woman who was raped by an Uber driver in 2014. The review was to focus in part on accusations from some current and former employees that bribes were involved, two people familiar with the matter told Reuters.

Khosrowshahi, 48, on Tuesday made his first public comments since the board's decision to make him CEO in two interviews in which he confirmed he plans to accept Uber's top job, despite the company's many problems. He made the comments at a previously scheduled event at Expedia's headquarters in Bellevue, Washington.

"Are there difficulties? Are there complexities? Are there challenges? Absolutely, but that's also what makes it fun," Khosrowshahi told Bloomberg. Khosrowshahi has not responded to inquires from Reuters.